Reciprocatory electric motor



' 1954 H. a... MOHENRY ETAL RECIPROCATORY ELECTRIC MOTOR Original FiledDec. 22, 1950 INVENTORSQ (j flaw/ er Patented Oct. 12, 1954RECITPROCATORY ELECTRIC MOTOR Harland L. McI-lenry, Sayre, Pa, andLeland 0.

Parker, Elmira, N. Y., assignors to Bendix Aviation Corporation, acorporation of Delaware Original application December 22, 1950, SerialNo.

202,162, now Patent No. 2,666,153, dated January 12, 1954.

Divided and this application February 4, 1953, Serial No. 344,835

2 Claims.

The present invention relates to a reciprocatory electric motor and moreparticularly to an electromagnetic device for reciprocating a plungersuch as the piston of a fuel pump.

It is an object of the present invention to provide a reciprocationelectric motor which is efficient and reliable in operation while beingsimple and economical in construction.

It is another object to provide such a device which incorporates simpleand effective means for controlling the electromagnet.

It is another object to provide such a device in which all the movingparts of the motor are arranged to have rectilinear motion only, and arebalanced so as to be unaffected by accelerational forces lateral totheir path of movement.

Further objects and advantages will be apparent from the followingdescription taken in connection with the accompanying drawing in which:

Fig. 1 is a vertical substantially midsectional view of a preferredembodiment of the invention showing the parts in idle position;

Fig. 2 is a fragmentary section showing the parts in the positionsassumed when the piston approaches the lower end of its stroke;

Fig 3. is a view similar to Fig. 2 showing the parts in the positionsassumed when the piston starts up on its discharge stroke.

In Fig. 1 of the drawing there is illustrated a cylinder l ofnon-magnetic material in which is slidably mounted a hollow plunger 2 ofmagnetic material such as soft iron. The upper position of plunger 2 isdefined by a cylindrical stop 3 of suitable material such as fiber. Aspring 4 urges the piston upward toward said stop, and means forovercoming the spring and drawing the piston downward is provided in theform of a solenoid 5. Circular pole pieces 6 and i are located at theends of the cylinder and serve to locate the solenoid and the cylinder lwithin a cylindrical housing 8 of magnetic material which serves tocomplete the external magnetic circuit of the solenoid.

Means for energizing the solenoid 5 is provided comprising a battery 9which is grounded at H and connected through a switch i2 and a lead 13to a contact M mounted on a resilient blade [5 attached to but insulatedfrom the cas ing 8 as indicated at It. A second contact ll adapted tocooperate with the contact Hi is connected by a lead it to one terminalof the solenoid, the opposite terminal of which is grounded at l9 tocomplete the electrical circuit. Means for controlling the contacts I4,I! is provided comprising an electro-magnet H which is slidably mountedon the exterior of the cylinder i. One terminal of the electro-magnet 2iis connected by a lead 22 to the battery lead 83 and the other terminalis grounded as shown at 23 so that the electro-magnet is energizedcontinuously as long as the switch 82 is closed.

Electro-magnet 2! is provided with a casing 24 of magnetic materialwhich serves to oomplete the external magnetic circuit thereof, and isurged upwardly by a spring 25 so as to cause said casing toengage thefree end of the blade 15' and move the contact Hi out of engagement withthe contact I1. The parts are so arranged that when they are in idleposition as shown in Fig. l, the plunger 2 has entered part way into theelectro-magnet 2i whereby energization of the electro-magnet willattempt to draw the plunger upward, and since this movement of theplunger is prevented by the stop 3, the electro-magnet will movedownward so as to allow contacts Hi, I"! to close.

In the operation of this embodiment of the invention, starting with theparts in the position shown in Fig. 1, closure of the switch 82 causesenergization of the electro-magnet 2! which thereupon moves downwardagainst the force of the spring 25, and permits contacts i l, I! toclose. The consequent energization of the solenoid 5 causes the plunger2 to move downward as shown in Fig. 2, drawing the electromagnet 28 withit until the electro-magnet is arrested by the spring 25. This springthen becomes effective to return the electro-magnet to its upperposition as shown in Fig. 3, opening the contacts l4, ll. The consequentdeenergization of the solenoid 5 permits the spring A to move theplunger 2 upwardly until it enters the elec tro-magnet 2i sufficientlyto again cause the electro-magnet to move down and close contacts Hi, i?whereupon the operation is repeated.

In order to utilize this motor as a pump, the casing 8 is provided withan inlet 26 and an outlet 21, and chuck valves 28 and 29 are mounted inthe lower end of the cylinder I and the upper end of the plunger '2respectively.

This is a division of application Ser. No. 202,162, filed December 22,1950, now Patent No. 2,666,153, January 12, 1954.

Although certain structural features of the invention are shown anddescribed in detail, it will be understood that other embodiments arepossible and that various changes may be made in [the design andarrangement of the parts without departing from the spirit of theinvention.

We claim:

1. In a reciprocating electromagnetic motor a solenoid, a non-magnetichollow cylinder fixed in the solenoid and projecting therefrom, a pistonof magnetic material slidably mounted in the cylinder, an abutmentlimiting the projection of the piston from the solenoid and thusdefining its idle position, a spring urging the piston toward idleposition and cocked by the movement of the piston responsive toenergization of the solenoid, a cylindrical casing of magnetic materialsurrounding the solenoid, annular pole pieces of magnetic material atthe ends of the solenoid supporting the solenoid in the casing andproviding with the casing a path of low reluctance for the portion ofits flux circuit external to the solenoid, an annular magnet on theprojecting portion of the cylinder, surrounding the projecting end ofthe piston and movable therewith by mutual attraction; means forenergizing the solenoid including a pair of contacts biased towardclosed position, means responsive to movement of the magnet away fromthe solenoid for opening said contacts and a spring operative at the endof the cocking stroke of the piston to overcome the mutual attraction ofthe magnet and piston and move the magnet to open the contacts andthereby deenergize the solenoid.

2. An electromagnetic motor as set forth in claim 1 in which the magnetis in the form of a ring surrounding the cylinder with poles arrangedaxially of the cylinder, said abutment for the piston being so locatedthat the end of the piston is within the magnet when the magnetisholding the contacts open.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,640,742 Wallace et a1 Aug. 30, 1927 1,903,902 McLaren Apr.18, 1933 2,468,343 Parker Apr. 26, 1949 2,472,067 Dickey June '7, 19492,472,334. McHenry June 7,v 1949

